This invention relates generally to a manually operated dispenser, in the form of a sprayer, of the pressure accumulating type, and represents alternative embodiments over the sprayers according to my U.S. Pat. Nos. 4,494,680 and 4,511,065, which are in turn improvements over my earlier U.S. Pat. No. 4,050,613. Specifically, the manually actuated pump according to the present invention has an upright discharge nozzle facilitating its use as a nasal sprayer, for example, and is structured to facilitate accurate output control of the sprayer.
In the manually actuated dispensing pump according to my U.S. Pat. No. 4,494,680 the plunger is isolated from lateral or eccentric forces which may be applied to the plunger head, so that the plunger which functions as a discharge valve is free from restraint by frictional engagement due to opposing force couples or lateral pressure and will therefore respond continuously and promptly in the intended operating mode in balance between the hydraulic pressure and opposing spring force. The pump has spaced bearing members for guiding the plunger head to effect isolation of the plunger during operation.
Another feature of such dispensing pump includes the plunger having a perforated top wall defining a surface facing the upper end of the piston and complementarily contoured thereto, such wall permmitting the plunger to bottom out against the upper end of the piston before the end of the plunger head downstroke thereby allowing for further depression of the head so that it will continue to expel product through the discharge passage upon further depression thereof as the plunger moves into its discharge closing position.
And, in the manually actuated dispensing pump according to my U.S. Pat. No. 4,511,065 the piston is separate from the pump body and is of a softer and more pliant material than the pump body, to thereby achieve a rugged and durable pump body which includes the closure cap, while at the same time obtaining an improved piston quality with improved piston lip seal definition.
The present dispenser provides for upright discharge, in the form of a nasal sprayer, while at the same time facilitates accurate control of the sprayer output. Nasal sprayers having upright discharge are known, as are dispensers providing for controlled output, as set forth in U.S. Pat. No. 4,245,967. However, such a sprayer is not of the pressure accumulating type but rather requires lost motion between the plunger and piston to open the discharge. Moreover, the amount of spray is controlled by the length of a filler element on the piston for controlling its stroke.
Other controlled output or precise dosage dispensers are disclosed in, for example, U.S. Pat. Nos. 3,458,090, 3,653,556, 3,990,611 in the form of adjustable stroke pumps. Again, these are not dispensers of the pressure accumulating type to which the invention is directed.